Lens holder



July 4, 1944. w. P. cANNlNG LENS HOLDER Filed Feb. 16

WILLIAM P. CANNING INVENTOR A ORNEY Patented July 4, 1944 UNITED STATES PATENT OFFICE LENS HOLDER William'P. Canning, Southbridge, Mass., assignor to American Optical Company, Southbridge, Mass., a voluntary association of Massachusetts Application February 1s, 1942, serial No. 431,133

(ci. 51z16) 6 Claims.

This invention pertains to a supporting block or holder for an article which is to be subjected to various treatments of fabrication and has particular reference to novel means and method of blocking and of forming a lens block having a. disposable portion formed of a material which may or may not be simultaneously subjected to said treatments.

One of the articles particularly adaptable for use with a supporting block or holder of the character described is a lens. Heretofore, when a lens which was finished on one surface required treatment on the unmshed surface thereof, said lens was first blocked by securing the lens to a metallic lens block either by use of pitch or some other adhesive for holding the lens in position on said lens block.

In following such a procedure, after the second surface of the lens was finished the lens was then removed from the block and carried through further steps of processing such as cutting, edging, drilling, etc.

In following such a procedure particularly with lenses having prescriptive corrections other than straight spherical powers, for example, lenses requiring a cylindrical power for correction of astigmatism in a given meridian or having embodiedtherein a prismatic power requiring the l-ns`to be maintained in a given axial position relative to the various holders of the respective devices for performing the various steps of the process' set forth above, great care had to be taken to maintain the actual relation of the lens with the various holders in order to arrive at the proper prescriptive correction and proper support of the lenses in desired axial position before the eyes.

The present invention overcomes the above difficulties of maintaining axis, etc. through the provision of a disposable type backing support for the initial blocking device or holder, which holder is utilized throughout the various stages of fabrication of the lens. This holder in addition to retaining the lens in proper axial position throughout the various stages of fabrication also enables the performing of said various operations with greater ease and accuracy and with less tendency of error and breakage of the .lens material.

One of the principal objects. therefore, is to provide such a disposable blocking device` or holder formed of a material which may be cut and broken away within the forming of the lens to the contour shape and size desired, which may with the edging of the lens and which may be drilled with the material of the lens during the drilling operation and thereafter be replaced by another disposable support through attachment to a permanent metallic portion of the blocking device or holder.

It is a further object of the invention to provide a disposable block portion for treatment of a lens so that the said block itself gives sufllcent support to the edge of the lens While being abraded and may be broken away with portions of the lens and may be cut by an edging wheel without destroying the permanent metallic portion of the block to which the disposable portion is secured.

It is a further object of the invention to provide a plastic backing member for a lens so that the lens may be drilled completely through from one side withoutI any appreciable damage to the underneath surface of the lens as might be caused by chipping or aking of the glass while being drilled.

It is a further object of the invention to provide a plastic blocking member to be secured to one surface of the lens to be treated, which blocking member may remain secured to the lens under treatment during the grinding and polishing operation, cutting operation, edging operation, and the drilling operation.

It is a further object of the invention to provide `convenient means and method of produc-L it is a further object of the invention to provide a disposable backing or blocking member for a lens, said backing or blocking member being made of a plastic such as methyl methacrylate or the likeso that the backing member will give adequate support to the lens during treatment and which may be mutilated during the course of treating the `lens without said plastic material being too costly for disposal when no longer fit for use.

It is a further object of the invention to provide a disposable blocking portion or holder and novel method of blocking a lens which will retain the lens in proper axial position throughout the various stages of fabrication of said lens.

It is a further object of the invention to provide a disposable backing support or holder for a lens having self adhering characteristics for supporting and retaining the lens on said block vide a disposable blocking portion or holder having characteristics. which will provide relatively rigid contact means in combination with self adhering characteristics by which a lens may be held in proper relation with said contact means during the various stages of` fabrication.

It is a further object of the invention to provide a backing support or holder for a lens which may be secured to the various devices for performing different operations on said lens in a given axial position in said respective devices.

Other and further objects may be and may become apparent from a perusal of the disclosure in the present application and it is `to be understood that the'present drawing is by way of illustration only, and equivalent parts may be utilized within the spirit of the invention as set forth in the subjoined claims.

In the drawing:

Fig. 1 is a plan view of a lens.

Fig. 2 is a sectional view of Fig. 1 showing the lens secured to a disposable lens block by means of pitch or the like, while said disposable lens block is connected to a, metallic lens block by threadedlyconnecting the plastic lens block to the metallic lens block or by other suitable means. l

Fig. 3 shows the lens secured to the disposable lens block in position on a portion of a surfacing machine.

Fig. 4 shows the lens secured on the disposable lens block being edged for a rimless mounting.

Fig. 5 shows the lens and its plastic mounting in position to be drilled for securing said lens in an ophthalmic mounting. f

Fig. 6 is a modification of Fig. 4 wherein the lens is being bevel edged for mounting the lensv in an eye wire of an ophthamlic mounting.

Fig. 7 is a fragmentary view illustrating the cutting step in the process of producing the article embodying the invention.

Referring to the drawing and more particularly to Fig. 1 a top view of a lens 1 is shown indicating that it is round in shape. While the lens is shown round in Fig. 1` it is to be understood that any of the conventional shapes may be used in any one or more of the various steps set forth herein but, for convenience, a round lens is shown.

The lens 1, as shown in Fig. 2, is secured to the lens block portion 8 which will hereinafter be referred to as a disposable block portion. In this particular instance, the lens 1 is shown as being secured to the block l by means of an adherent such as pitch or other suitable means which is commonly utilized to secure a lens to a lens block. The disposable portion 8 has a threaded recess 38 therein adapted to receive the threaded end 31 of a permanent block portion III preferably formed of metal; or other suitable wear resisting material. The permanent lens block portion l0 has a tapered opening 38 therein adapted to receive the tapered end 39 of a supporting stud which is of a standard size and shape for each of the respective devices by which the blocked lens is to be carried throughout the different stages of fabrication. By this it is meant that each of the devices, shown diagrammatically in Figs. 3, 4, 6 and 7, for performing the various steps of the process are provided with a supporting stud portion simulating the stud portion 39 illustrated in Fig. 2 whereby the permanent block portion Il may be supported in a given axial relation with the supporting `zuds throughout the various stages of fabrica- To locate the lens 1 in a given axial position or relation with the supporting studs 39 of the various devices the said studs are each provided with a locating pin IU adapted to fit within a slot 4l in the permanent blocking portion I0.

By following this procedure it will be seen that a lens 1 supported by the blocking means or holder, which constitutes the disposable portion I and permanent portion I0, will be held in a given position relative to the abradlng tool of the abrading device during the forming of the second surface thereon. Such an abrading machine is diagrammatieally illustrated in Fig. 3. If the second or final surface of the lens 1 is of a cylindrical or toric type having predetermined meridinal axes as formed by conventional cylindrical or toric abrading machines known in the art, the said axes will be disposed in a given position relative to the pin and slot connections between the stud and permanent portion I0 and will retain this relation throughout the various stages of fabrication. Due to the fact, therefore, that the lens does not have to be removed from the disposable holder or block portion 8 as has been usual with prior art blocking devices all off-axis errors which might occur through the successive removal and placement of the lens in the different holding means of the various devices is eliminated.

The disposable portion l may be formed of an organic material capable of being cut or crumbed and edge ground or drilled at the same time the lens is subjected 'to such steps of fabrication.

The material may be loaded or unloaded, that is to say, it may consist of a resinous support of the nature of polyme d methykmethacrylate, poly styrene, cellulose a etate or other esters of cellulose or similar organic materials having like characteristics of ready workability without the incorporation of discreet particles of fibre or other means. It may consist of materials similar to those described above having incorporated with it, at or before the time of fabrication, organic or inorganic particles or fibres, such as wood, flour, precipitated chalk, mica, talc as examples of non-fibrous loading materials and asbestos, cotton linters, wood fibres, shredded paper, shredded cloth or the like, examples of fibrous loading materials with the thought that these loading materials will function as a satisfactory contact or self shape retaining backing support for the lens with the bondingmaterial simultaneously functioning as a backing support for retaining the shape ofthe attachment-surface for the lens holder or` block. 'I'he filler material tends to increase the rigidity and shaperetaining function of the backing support to provide a suitable support for the lens during the various stages of the fabrication thereof.

The bonding material may be of such a nature as to serve itself as adhesive for holding the lens member in contact throughout the various operations. As an example of this type of construction the resin' used may be various naturally occurring resins such as rosin or processed resin such as rosin esters and compounds of rosin with inorganic materials such as lime winch serves to raise the melting point and decrease the brittleness, lower the susceptibility to thermal shock and reduce the solubility in some of the solvents t9 Which the assembly may be exposed during assaeio temperatures thereby serving to cause the lensesto adhere thereto, a'nd may possess the filler materials set forth above. in which instance the nner materials will function as reinforcing agents forming a positive contact or backing. support for the lens with 'the bonding materialk functioning as the adhesive.

One of the essentials is that the backing sup- Dort be of such a nature that it may be worked simultaneously with the working of the lens. By this it is meant that it may be cut and crumbed, may be ground away with the material of the lens during the edging thereof and may be drilled with the drilling of the lens. The main feature is that after the lens has once been locked to the support, the said lens, as well as the support, may be carried through the various steps of the processing until the final step of the process has been carried out: after which the lens may be removed from the support.

Fig. 2 shows the lens 1 secured to the lens block 9, which lens block may be made of any of the materials or compounds mentioned above. rIfhe lens 'l is secured to the lens block I by means of an adherent, such as pitch 9, which is commonly utilized to secure a lens to a lens block but it is to be understood that the block 8 may be of the type formed of self adhering materials or compounds.

In Fig. 2 the lens block lis shown threadedly connected to the permanent lens block holder; il and while threads are shown on the lens block for securing the lens block to the lens block holder lt is to be understood that any suitable means may be used, such as by securing the lens block to the lens block holder by the use of pitch. While the use of pitch is specifically shown and described herein as one method of securing the lens block to the lens. it is to be understood that the lens Amay be secured to the lens block by using a suitable lamination with heat and pres- Sure.

In Fig. 3 there is diagrammatically shown a surfacing machine I I having an upper spindle `I2 revolubly supported in a bearing I3. 'I'he spindle i2 has a lapping tool i4 carried thereby and adapted to be rotated by a pulley and belt arrangement I5 and ii respectively. A lower spin.. dle II is mounted to be rotated by a pulley and belt i8 and .i 9 respectively. 'I'he upper end 42 of the spindle i1 is of the size and shape of the end 39 of the supporting spindle shown in 2 and has a pin 42 adapted to fit within the slot 4I of the permanent portion III of the lens block. This automatically locatesY the lens 'l in a given fixed position or axial relation with the spindle of the abrading machine. It is to be -understood that the abrading machine, illustrated in Fig. 3, is only by way of illustration of a' step of the process of manufacture or fabrication of a lens 'and that several other ditlferent `types of abratung machines commonly used in the art might be employed, for example, the machine diagrammatically illustrated in Fig. 3 is of the commonly known spherical' abrading type but the machines commonly known in the art for forming cylindrical or toric surfaces as well as surfaces of other compound curvatures might be used.

The bowl 24 rotates with the spindle in a conventional manner. The lens block -holder' il is shown connected to thesdisp'osable lens block l gages the lens lap glcilthe lens l issecured to said disposable In Fig. 3 the lens is mounted on a lensblock may now be rotated in conventional mann r so that the surface of the lens, which eniil, may be suitably ground andpolished. .Y Ordinarily when the lens l is delivered from the factory to the dealers in the field, one sur. face of the lens is suitably polished, while the field dealer puts on thek other surface lof the lens according to the individuals prescription. The disposable lensblock 3 is shown being of sub. stantially the same diameter as the lens I but it is to be understood that the dimension(i of the lens block may be of any size suitable to properly hold thelens while it isi being surfacededged and/or drilled.

In Fig. 4 there is diagrammatically illustratm a lens edging machine comprising spindles 2i and 22 for clamping the lens 'l and disposable lblock during the edging. operation. The spindles 2i and 22 are simultaneously rotated to causethe lens l to be rotated The lens 'l and disposable-block 9 are adapted to engage a rotating lens edging wheel 23 in the conventional manner. The spindle 22has an end 44 o'f the same type as the end 39 of the spindle illustrated inFig. 2 and has-a pm as adapted to at .within the not ofthe lens block holder i0. This, therefore, causes the lens I to be held in proper 'axis during the edging operation andv produces a relatively fiat edge known in the` art as a rirnless lens type edge.

In the view shown in Fig.-4 the diameter of the lens block maybe disposed of because it is of a` material that is reasonable in cost and easily obtainable. y

In Fig. 6 there is diagrammatically illustrated another type of lens edginghmachine commercially known as a bevel edger. This machine has spindles 2i and 22 simulating the spindles of. the machine diagrammatically illustrated inFig. 4. The edging wheel 24 which is mounted to rotate with a rotatable shaft 25 has a V-shaped groove in the periphery thereof adapted to form a V-v shaped bevel on the edge of the lens 1. The shaft 22 has a tapered end simulating the end 39 of the spindle illustrated nin Fig. 2 and has a pin 46 adapted to fit within the slot in the block holder i0. This, as in the edging machine ldescribed above, automatically locates the lens in proper axial position. By proper .axial rposition itis meant that the lens l will befdisposed in proper relation with the major axes of a. former. 41 carried by the shaft 22. This former 41 is adapted toengage a contact shoe 44 and is adapted to rotate simultaneously with the rtationof the lens I and its `purpose is to control the finished contour size and shape of the-lens. It is quite apparent that itis essential that the lens 'I beheldin proper axial relation wit h the axes .ofthe former in order to insure that the cylindricalaxes of the lens will be in proper prescriptive,positionwhen the mounting is completed. y yItwillw-be. seen .that the lens block 8 willalso be groundfdown .but this fact is immaterial since again it is pointed out that the lens block is made of a material which is intended for this purpose. The material is relatively low in cost-so that it may be disposed of when its size is reduced sumciently to render it unusable.

In Fig. 5 a lens drilling machine 26 is diagrammatically illustrated. It comprises a spindle 21 cures the lens in positional relation to the bed 3|.

In Fig. 5 the permanent lens block holder I0 has been 'removed from the disposable lens block l ard the holding member 33 is used to hold the lens in ilxed relation with the bed while it is being drilled by the-drill il which is held in a chuck 35. The edge of thef lens 1 and lens block l are held in engagement with' a suitable stop 49 during the drilling. This is to control the location of the hole relative to the edge ofthe lens.

It will be noted that the threads 38 in the disposable-lens block holder 8 are below the lens 1. In this position the lens 1 may be drilled'completely through the lens from one side thereof since the lens block holder has an intimate engagement with the lens by means of the pitch or by the heat and pressure method. Formerly when lenses were drilled for securing the lens straps to the lens by means of a connecting pin or screw extending through the hole the said hole was drilled in the lens from opposite sides thereof to prevent chipping of the lens adjacent the hole because of a lack of a suitable support on the reverse or bottom side of the lens.

With the present disclosure it is possible to drill completely through the lens from one side thereof with a minimum of chipping or aking of the" glass on the opposite side thereof. It will. therefore, be seen that once the lens is blocked on the lens block the lens may be surfaced, edged land drilled without removing the lens from the lens block until all of the necessary operations are completed. Ordinarily when a lens is edged, as is shown by the operaton in Fig. 6, the bevelled edge of the lens would flt into the eye wire of theophthalmic mountings; howeverl in the rim`- less type ofj mounting thel lens would be given a flat edge such as would result in the treatment disclosed in Fig. 4 with the flat edged lens resulting from the treatment in Fig. 4. The drilling operation, as shown in Fig. 5, would be necessary to secure the lens to the lens straps of the mount- To assist in locating the drill position at which the connection openings are to be drilled in the lens, particularly, in instances; when the lens is secured to a disposable lens block member 8 of the type which does not require an adhesive coating I, because of its self-adhering characteristics, the face of the disposable lens block l may be provided with an axis line, designated by the dash line 5l in Fig. l, which is so positioned relative to the pin and slot connection between the permanent holder il and the ends Il of the respective spindles as to designate the horizontal center line or mechanical axis of the lens. 'I'his line Il may. instead of passing through the center of the holder in the direction of the longitudinal axis of the pin lil, along said axis may be off-set above but parallel with the said line depending upon the .height at whichthe hole is to be drilled in the lens above the geometric horizontal center line of the lens. This line may be used as a guide in drilling the holes in the lens for the connection of the lens straps. By merely drilling the lens on said line at a distance inwardly of the contour edge of the lens, as determined by the adjustable stop I9 the locations of the connection openings may be quickly, easily and accurately determined.

In F18. 7 there is diagrammatically illustrated a lens cutter which has a supporting spindle Il simulating the spindle I9 to whiti the lens holder and lens may be quickly attached and supported in proper relation with a suitable cutting tool i2 in the usual conventional manner. The lens is cut by rotating the spindle 5I thereby causing the lens to rotate relative to the cutting tool 52 with the said cutting tool being guided in a given path during the rotation of the lens so as to cut the lens approximately to the shape desired in a conventional manner. The part of the lens which is to be removed from the contour thereof after the said lens has been cut, because of the particular nature of the disposable block 8, can be broken away with the material of said block by a crumbing process commonly used in the art. In this particular instance, the disposable block l is so controlled as toits brittleness as to enable it to be broken away with the part of the lens to be removed as resulting from the composition such as previously mentioned having suitable loading agents therein 'for controlling the 'plasticity and brittleness. This cutting operation is generally performed prior to the edging operations diagrammatically illustrated in Figs. 4 and'6.

The gist of the present invention is to utilize a lens block which may be made of a material which may remain secured to the lens throughout the various steps of the treatment, such as grinding, polishing, cutting, edging and drilling. By leaving the lens secured to the lens block it should be clearly obvious from the foregoing that the various steps of grinding, polishing, cutting, edging and drilling do not necessitate the removal oi the lens from the lens block. 'I'his feature permits the complete treatment oi' the lens by the dealer in the field and greatly reduces the time required to complete the lens prior to placing the lens in the ophthalmic mounting.

While methyl methacrylate and poly styrene have been referred to as suitable materialsfor the disposable lens block, it is to be understood that any suitable material having the characteristics desired may be used which will permit the lens block to remain secured to the lens through the steps of grinding, 'p0lishing, edging, drilling, etc.l when necessary. While the disposable lens block has been referred to as being made of a plastic, such as methyl methacrylate, the material poly styrene,

or the like, is also specifically mentioned as suitable. Not only may a plastic material be used. but a thermoplastic material may be employed,

lor a thermo-setting plastic may be utilized.

In the edging and drilling operation, the lens to be processed or treated may use the lens block as set forth herein. However, the drilling operation may employ the lens block of a disposable material, with another piece of material, somewhat similar in shape to the lens block, cemented on the opposite side of the lens so that there will be a piece 'of disposable material on both sides of the lens for the drilling operation. 'I'his feature may be desirable since it has been found that the avoidance of chipping of the lens is minimized on the front surface of the lens by the addition assaeie of the second piece of material being cemented to the lens on the opposite side of the lens block for the drilling operation.

The use of the disposable material on the front of the lens is advantageous particularly when a very fine Job of dri g is required. In commercial practice, there ay be some slight chipping when the drill enters the first surface on the lens to be drilled, and with the present process of utilizing the front piece of plastic or glasson the lens to be drilled the possibility of chipping is minimized.

In the specification, it has been set forth that the methyl methacrylate lens block may' be secured to the lens by pitch or other suitable means. It is to be understood that any suitable cementing means may be used which causes the lens to be suitably adhered to the lens block. Another example of a. good cement is sealing wax, since sealing wax is quite hard and will also provide a stable bond between the lens andthe lens block, or the lens and the front cover when the front cover is .used in the lens treating operation.

It is also to be understood that blocks of material other than methyl methacrylate might be used either with or without loading agents in which instance the bonding material may be of a self-adhering type requiring no separate layer of adhesive. With the latter arrangement the lens 1 may be attached directly to the supporting surface of the disposable block portion 8 by merely slightly heating the lens to a temperature suillcient when placed against the supporting surface of the disposable block 8 to cause the said block or supporting surface of the block to superflcially soften and become tacky whereby the lens will adhere directly with said surface.

In instances when a filler is used with the bonding material of the disposable member, the filler material, when the disposable block portion is initially formed to shape, will be so shaped that the portions thereof adjacent the supporting face will lie in the plane or surfaceline of said supporting surface. When the bonding material is supercially softened by heating it will tend to expand and slightly ooze out from between the filler material thereby causing the ll'er material to provide substantially rigid contact means on which the lens may be pressed with the said supercially softened bonding material tending to adhere with the adjacent surface of the lens and upon cooling will tend to contract and cause said lensto be rigidly held in engagement with the ller material.

By reason of the fact that each ofthe devices used in performing the various steps of the process of producing the lens have substantially identical attachment means for receiving the lens and supporting block whereby the lens can be permitted to remain secured to the supporting block throughout the various steps of the process the various different steps may be more quickly, easily and economically performed with the resultant lens having greater prescriptive accuracy as all possible error, due to improper location of the lens in various separate holding means as with the devices of the prior art, have been eliminated. The necessity of prelocating and marking the optical axes on a lens for use as guide means in positioning the lens in the various holding means of the devices used in the processing thereof has been entirely eliminated. It has been usual in the past to block a lens on a lens holder, abrade the nal corrective surface thereon, remove the lens from the block, clean the lens, and place the lens in the axis locating and marking device. This provided guide marks on the lens which had to remain thereon throughout the remaining steps of the process of cutting, edging, drilling and so forth. When transferring the lens from one device to another great care had to be taken in locating the axes of the lenses in proper aligned relation with the holder thereby introducing possible error at each stage of the process. The lens, when placed in the holder, did not only have to be located in proper axial position but the opti" cal center thereof had also to be carefully located in a given position. Also. in the past, the lens itself had to bear the brunt of the strain introduced during the performing of the various steps of the process thereon and thereby introduced danger of spoilage due to breakage.

With the present invention all of the above difficulties are eliminated and the loss of time required by the prior art procedure is also obviated. Means-.is also provided for protecting the lens against breakage by relieving strain thereon during the performing of the various stages of the process. In addition to the above the present invention insures optical precision and absolute accuracy in the completing of the mounting for permanent wear before the eyes. 1"

Having described my invention, I claim:

1. A lens block adapted to receive a lens comprsing a portion of non-metallic material having a surface shaped substantially to the shape of the surface of a lens to be attached thereto vand covering substantially the entire surface of the glens,

said portion being relatively thin adjacent the' periphery thereof and having a central recess with attachment means therein on the side thereof opposite the surface shaped substantially to the lens and a holder having an attachment end portion adapted to ilt within the recess and having attachment means adapted to be connected with the attachment means in the recess whereby the non-metallic portion may be detached therefrom after performing theextent of its usefulness and a new non-metallic portion attached thereto, said holder having a portion opposite its attachment end provided with connecting means for attachment to a standardized attachment member of a plurality of different optical instruments and machines whereby aplurality of successive operations may be' performed on the lens while said non-metallic portion is in secured relation therewith with a portion of the material of said nonmetallic portion being removed with the materialv of the lens during said different operations whereby the said portion of non-metallic material may thereafter be removed from the lens and holder and be disposed of.

2. In a device of the character described a block of non-metallic material having an attachment surface thereon shaped substantially to the surface of an article to be attached thereto, said member being relatively thin adjacent the periphery thereof and having connecting means centrally thereof on the side opposite the surface shaped substantially to the surface of the article, a holder having an end portion with connecting means adapted to be detachably connected with the connecting means of said member, said holder having an attachment portion adapted to t standardized attachment means on a plurality of different machines for performing different operations on said article whereby said'article and said non-metallic member may be connected with each other and retained 1n said relation throughout said various operations with the said member'being adapted to be subjected to the samev treatment as the articl during said operations. I

3L A l'ensblock comprising a relatively thin disc of non-metallic material having an attachment surface thereon to which a lens is connected, said attachment surface being shaped substantially to the surface of the-lens to which it is connected and having attachment means to which a separable holder is attached, said holder having a portion adapt'ed to fit standardized at- 4. In a device of the character described for` use in combination with a lens during the performing of various operations thereon, said device comprising a backing support having a surface shaped substantiallyy to and to which the lens may be attached. said backing support beingeformed of non-metallic material and having al relatively thin portion adjacent the periphery thereof and having attaching means thereon to which a holder member may be detachably connected, said holder member lhaving an attachment portion on the side thereof opposite the i backing support shaped to fit a lplurality of standardized attachment means of different maL chines for performing different operations on said lens, said lens and backing support being adapted to be retained in connected relation with each other during the-performing of said 'different operations, said backing support being such as to respond to treatments similar to the -treatment received by the lens during the performing of said operations and being adapted to be thereafter removed and disposed of.

5. In a device -oi' the character described for use in supporting a lens for the performance of various dierent operations thereon, said device comprising a supporting portion of nonmetallic material having a surface shaped substantially to the shape of thelens attached thereto and Ibeing relatively thin adjacent its peripheral contour, said supporting-portion having connecting means on the side thereof opposite the attachment surface for the lens, a metallic holding member having attachment means for connection with the attachment means of the supporting portion and having an opposed attachment end adapted to be connected to standardized attachment means on different machines for performing said different operations, the said lens and said supporting portion of non-metallic material being so proportioned and related with each other and permanently retained in connected relation so that a portion of the material of the non-metallic supporting portion is removed with the material of the lens during the performing of several of said operations.

6. In a device of the character described a block of non-metallic material having an attachment surface thereon to receive an article to be attached thereto, said block being relatively thin adjacent the periphery thereof and having connecting means on the side thereof opposite the attachment surface, a` holder having an end portion with connecting means adapted to be detachably connected with the connecting means on said block, said holder having an attachment portion adapted to t attachment means on a plurality of different machines for performing different operations on said article whereby said article and said non-metallic block'may be connected with each other and retained in said relation throughout said variousoperations with said block being adapted to be subjected to substantially the same treatment as the article during said operations.

WILLIAM P. CANNING. 

